Objective To research the possible antiangiogenic mechanism of Xinfeng Capsules（新风胶囊）for rheumatoid arthritis（RA）.Methods Fifty SD rats were randomized into the normal control group

model control group

Methotrexate group

Tripterygium Glycosides Tablets group and Xinfeng Capsules（新风胶囊）group

with 10 in each.The adjuvant arthritis rat models were established with Freund’s complete adjuvant.After modeling

the Xinfeng Capsules（新风胶囊）group was gavaged with 2.4 mg / kg Xinfeng Capsules（新风胶囊）solution once daily.The Tripterygium Glycosides Tablets group was gavaged with 10 mg / kg Tripterygium Glycosides Tablets solution once daily.The Methotrexate group was gavaged with 3 mg / kg Methotrexate solution once weekly.The normal control group and model control group were gavaged with 1.0 mg / kg normal saline once daily.The intragastric administration lasted for 30 days.The plantar swelling degree and arthritic index was measured.The expressions of hypoxia-inducible factor-1α（HIF-1α）and vascular endothelial growth factor（VEGF）were observed.The synovial microvessel density（MVD）was counted.Results Comparing with the normal control group

the plantar swelling degree

arthritic index

MVD

VEGF expression and HIF-1α expression was significantly increased in the model control group（P < 0.01）.Comparing with the model control group

the plantar swelling degree

arthritic index

MVD

VEGF expression and HIF-1α expression was significantly decreased in the Methotrexate group

Tripterygium Glycosides Tablets group and Xinfeng Capsules（新风胶囊）group（P < 0.05 or P < 0.01）

especially HIF-1α expression in the Xinfeng Capsules（新风胶囊）group as compared with the Methotrexate group and Tripterygium Glycosides Tablets group and VEGF expression in the Xinfeng Capsules（新风胶囊）group as compared with the Methotrexate group（P < 0.05）.Conclusion Xinfeng Capsules（新风胶囊）has an antiangiogenic effect by reducing the expressions of VEGF and HIF-1α in synovial tissue.